A novel polypeptide; a polynucleotide encoding this polypeptide; an expression vector containing this polynucleotide; cells transfected with this expression vector; an antibody against the above polypeptide; a method of screening an inhibitor for the polypeptide; a method of screening an antiobestic agent; and a process for producing the above polypeptide. The polypeptide as described above is a novel potassium channel expressed in the hypothalamus.
